Are ganglion cysts and pregnancy related?

No: I never read or observed that corellation. Cts and dequervain could be related to pregnancy.

Typically no: A ganglion cyst is a benign fluid filled sac, commonly presenting as a compressible soft tissue mass on the back of the wrist. They are usually not associated with pregnancy, but may be associated with previous trauma which may have created a small tear within the ligaments and capsule of the wrist. Over time, the accumulation of joint fluid creates a cyst which may wax and wane in size.